On Demand Hot Water?

Hi there--

We're installing a new bathroom on the 3rd floor of our circa 1910 home. The first plumber that we booked to do the job recommended that we get an on demand hot water heater for that bathroom since it's located so far away from our existing water heater.

Unfortunately, he can't do our project after all because of a serious health issue that suddenly came up (his intestines burst!). The plumber that we just interviewed for the project is familiar with on demand systems but hasn't actually installed one and doesn't have any make or model recommendations.

My questions for you are:
1) Does anyone have any recommendations on brands or models that we should look at? The heater will only be handling water for 1 bathroom and we'd prefer to have it run off electric as getting gas up to the 3rd floor would be difficult.

2) Is it risky to have a plumber that's never installed on of these units do it or is the installation something that any competent plumber should be able to figure out?

Thanks in advance for any and all advice!

Jude

avoid them if youcan

I know that this will start the on-going debate all over again about those peskey little jewels....


http://www.weilhammerplumbing.com/houseofhorrors/

Your best solution is a small Point-of-Use heater such as the Ariston GL2.5 or GL4. It will run on 115 Volts. If you have 50 ft of 1/2" pipe from your water heater, then you can go with the smaller one. If you have a long run of 3/4" hot water pipe, then you may want the larger one.

When you turn on a shower or sink at the remote bathroom, the Point of Use heater will immediaely deliver water. The water from your hot water heater, which has cooled in the line, will mix with the hot water in the POU heater. Before the water from the POU heater cools off significantly, the hot water will arrive from your standard heater.

The electrical and plumbing for the POU heater, including the heater, will cost about 10% of the electrical and plumbing and cost for the electric instant heater.

The electric instant heater will require a very large electrical circuit, possibly including a new service which can cost $1500.

The other decent alternative to Bob's suggestion (which I think is probably the better one) is to put in a hot water recirculator system. This could be an on-demand system, or one that runs on a timer, or a thermostat. It pumps hot water through a return line (if you don't have one, you use the cold water supply) until the water at the sensor is hot, then it stops. Basically, it pulls hot water from the heater until it gets to the sensor and then stops, keeping the line hot. This way, you have nearly instantaeous hot water. It also primes the lines for those things before it with hot so you get much quicker or instant hot water, too. It does waste energy since the pipes probably aren't that well insulated.

Wow--Thank you all so much for these suggestions (and warnings)!!!

With the Point of Use system, can one unit be attached to the sink, bath and shower or does each need its own unit? I looked at the Bosch website but couldn't quite tell.

Also, how bad to you guys think it's really going to be?

Taking into account both lateral and vertical distance from the water heater to the 3rd floor bathroom, we're looking at a maximum travel distance of around 50' from water heater to farthest fixture.

Would it be reasonable to just install the bathroom see how long the wait is for hot water and then install a Point of Use system if the wait's intolerable?

Thanks again!

Jude

master plumber mark said:

I know that this will start the on-going debate all over again about those peskey little jewels....


http://www.weilhammerplumbing.com/houseofhorrors/

Click to expand...

That's a joke, right?

I never joke

usually once this taknless subject is brought up
it generally starts a big debate.....
pros and cons...ect.ect.....blah blah blah



if the guy were to get himself a tankless electric
heater he will probably have to bring in a bigger
electrical service into the home thats will cost $$


and might I also suggest that he strap down the meter
with something to keep it from shakeing off the wall
when the tankless unit is heating....




all this trouble just to keep from runing
50 feet of 1/2 pex pipe tothe new bathrooom

Well, my two cents... I would suggest, as someone else did, a recirculator. I call it Instant Hot. I put one in myself for about $170. It has a valve at the furthest point from the HWH (I easily exceed 50') and and I have hot water as near instant as possible.

In fact, my town allows for a rebate of up to $200 for these things. It saves water. I didn't do it because requires an inspector to check for proper install to code etc... Why invite an inspector if you don't have to, right?

Anyway this thing has a dial-like timer on it, I basically have it on only during morning and evening times as that is when we need it. That helps keep the running costs down as it is only on when I need it.

Thought an opinion from a non-pro might help.

Anyway, good luck.

If you put in a Point of Use or a circulator, hook it up so it serves all of the hot water in the bathroom. If you have 50 ft of 1/2" pipe, you can use the GL2.5 POU.

If you use a circulator, be sure you do a good job of insulating the hot water pipe.

Whatever you do, install it initially. It will cost less.

I think the POU will save energy and the circulator will be a little smaller package. If you heat your water with electricity, I would go with saving energy.

Both are good.

Jim's right and Bob's right and both can ge right at the same time while preferring one or another option. You can also install both, together.

Other factors will determine which of the two you will choose. Some examples. Your local climate. Your building, how it was built and insulated. Your use of hot water in other parts of the house, and what size your hot water heater is. Do you ever run out of hot water? How good would you feel to have instant hot water? How irritated would you feel to hear the noise of a POU?

To say that some energy is lost, is true (when recirculating), but let us try to put a dollar figure on this. Pennies. The heat spreads out slightly everywhere in your walls and building, so it is not lost but transferred to, or gained by, the building structure. In winter that is a GOOD thing, and in summer not good, since the AC needs to work a couple percent harder or longer. Foam tube insulator, at ten cents a foot, is good since it reduces heat transfer to your building. With or without an insulator, you will never be able to feel any temperature difference more than one degree with your bare hands on a wall, and never with a thermometer in a room. That much I do know.

David